nc NOTOGAEA, NEOGAEA, AND ARCTOGAEA &5 the realm of Notogaea), and Madagascar; and finally, the realm of Antarctogaea or Atheriogaea, which embraces JSTew Zealand, the Antarctic continent., and a series of islands such as South G-eorgia and Kerguelen, and possibly even the extreme south of Patagonia. This latter quarter of the globe will need no further reference, as it has no truly indigenous terrestrial mammalian inhabitants. We cannot include the Bats in this statement, as their distribution is due to different powers of extending their range, and to different barriers from those which govern the range of other groups of mammals. (1) I^otogaea.1 This realm is characterised by the exclusive possession of the Monotremes:—that is to say, one of the two primary divisions of the Mammalia is ahsolutely restricted to this area. It contains, moreover, the vast majority of the Marsupials. Further, the realm of ISTotogaea is to be dis- tinguished by the entire absence of the higher mammals, with the exception of a few small Rodents. (The Bats are ignored for the reasons stated, and the Dingo is believed to have been an importation.) It cannot be disputed that this is a very distinctly- marked area of the earth's surface. (2) JSTeogaea. The continent of South America has no Monotremes and only a few Marsupials, all of which, with the exception of Caenolestes, belong to the Polyprotodont division of that order, and to a peculiar family, Didelphyidae. The recent discovery of other fossil Marsupials, however, to some extent favours Huxley's view that 3STeogaea and ISTotogaea form one realm as opposed to the rest of the world. Besides this, IsTeogaea possesses the Edentata, which are found nowhere else ;---- that is, the division of the Edentata to which the name is now restricted by some authorities. It is also characterised by the nearly entire absence of the important order of Insectivora; and, as minor marks of distinction, by the absence of Antelopes, Oxen and Sheep, of the Ichneumon tribe, of Horses, and of Lemurs. It has the exclusive possession of the Hapalidae and Cebidae, and of several families of Rodents. (3) Arctogaea. This vast realm is clearly capable of sub- division into four regions, which will be considered in detail later. In the meantime the points of likeness between these sub- divisions is more marked than are either the resemblances or the 1 This term, ia sometimes used in a wider sense ; cf. voL viii. p. 74.